When to winterise? And, drain or not to drain, that is the question.

SeaWeavers

SeaWeavers

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Hi all

My Bowrider (Mercruiser 3.0) is out the water on a trailer, I was thinking of waiting until the end of October until I winterise ( I want to try and get out before then if we get a good weekend!). Is the end of October to early? Do you guys with your boats out the water leave it later?

Another question regarding the pink anti-freeze you put in the cooling system. Once you have flushed through the cooling system with antifreeze do you leave it in there or do you empty the antifreeze out leaving the cooling system empty? I've watched every youtube video I can find, some miss out this point out, only one showed they empty it out. What do you guys do?
 
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End of October should be fine, but watch the weather forecasts as if it freezes.....

We dont have as a rule the kind of temperatures low enough that antifreeze fails if used to specification so the adage air dont freeze may be surpassed by any anti corrosion benefits the antifreeze holds. Choice is yours.
 
SeaWeavers said:
What do you guys do?
Click to expand...
Not my problem anymore, but I've been based in the N Adriatic for many years.
Up there, each and every boat is winterized. And all yards, bar none, do NOT drain the circuit after flushing with antifreeze.
Which makes perfect sense, imho: a humid and salty atmosphere is bound to facilitate corrosion of any metal parts much more than the contact with liquids meant to be not only resistant to freezing, but also to inhibit corrosion.
Don't forget also cylinders fogging, followed by intake sealing.
 
MapisM said:
Not my problem anymore, but I've been based in the N Adriatic for many years.
Up there, each and every boat is winterized. And all yards, bar none, do NOT drain the circuit after flushing with antifreeze.
Which makes perfect sense, imho: a humid and salty atmosphere is bound to facilitate corrosion of any metal parts much more than the contact with liquids meant to be not only resistant to freezing, but also to inhibit corrosion.
Don't forget also cylinders fogging, followed by intake sealing.
Click to expand...

Intaking sealing, how do I do that? I'm guess it's a plastic bag around the carburettor filter?
 
SeaWeavers said:
Hi all

My Bowrider (Mercruiser 3.0) is out the water on a trailer, I was thinking of waiting until the end of October until I winterise ( I want to try and get out before then if we get a good weekend!). Is the end of October to early? Do you guys with your boats out the water leave it later?

Another question regarding the pink anti-freeze you put in the cooling system. Once you have flushed through the cooling system with antifreeze do you leave it in there or do you empty the antifreeze out leaving the cooling system empty? I've watched every youtube video I can find, some miss out this point out, only one showed they empty it out. What do you guys do?
Click to expand...

Are we to assume you are in the UK as I cant see from your post/details ?
 
Id fill with a cheap automotive antifreeze and leave it in to act as a corrosion inhibitor.
Just be sure the engine is hot and stat is open (or even removed) or the antifreeze will just dump out the exhaust and not go round the engine.
 
Drain the block and manifolds. Poke the drains with a thin wire carefully to make sure there isn’t anything blocking them. Plugs back in..
Fill to the brim with AF at the thermostat big hose until it comes out the housing from engine being full. Fill the thinner hose there that goes to the manifold, until it comes out the alpha one drive.

Other things could be done previous to this too, depending how fussy you are.
But if you want to prolong the life of the engine and manifolds...fill it with AF for sure.
 
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